Does the GT28RS need a stronger...

jp · 10-12-2006, 05:35

...actuator? As in if it's fresh out of the box, does it need a strengthened actuator (e.g. HKS) to hold boost steady at 1.2bar? My T28 BB from the S15 is a little jumpy on the way up to when running 1.2bar & I'm wondering would a GT28RS have the same issue at that boost level? I've been told a strengthened actuator solves this issue!

JP

geavesie · 10-12-2006, 07:18

what boost controller do you use?

i have had a similar problem to this but i believe it was caused by a badly set up avc-r by myself

have a look at my graph below and see the wavey boost line

http://www.sxoc.com/vbb/attachment.p...3&d=1164556720

i have the gt28rs on a standard actuator and it seems fine now the avc-r is set up better

archenemy.co.uk · 10-12-2006, 09:40

I haven't got the turbo but people have posted about this before and the answer is yes, you would benefit greatly from the uprated actuator

At the moment your boost controler will have to raise the boost from something like 0.6 of a bar to 1.2. Thats a big jump and it makes the controller work very hard, so hard that it can loose its finer boost control or even just plain can't hold the boost

Get the adjustable Actuator and set it to just under a bar then you have a good solid base setting to work from

geavesie · 10-12-2006, 10:26

Quote:

Originally Posted by Mono Phil

Get the adjustable Actuator and set it to just under a bar then you have a good solid base setting to work from

makes sense i suppose

i'm still tuning my avc-r

it's a lot more stable and better all round now but if my problem comes back i think i'll go down the road of the adjustable actuator- cheers phil some good points there

sorry for the thread hi-jack

**SteA** · 10-12-2006, 10:42

Yes, you do

SM · 10-12-2006, 11:03

I find this funny, sorry, but a couple of years ago some people were complaining that the 15psi actuator the GT28RS came with was too strong, and they couldnt lower the boost enough, I think mainly due to them trying to use it on stock injectors while they got more funds together for other stuff. So back via suppliers to garret and they supply it with a weaker one, and now we are all turned on its head

Rich_D · 10-12-2006, 12:30

The actuator you get supplied with the GT28RS is actually the same one you get on the standard T28 (I bought one thinking it was better & it's the same one) so it's only rated for 7psi at actuator pressure and it will not hold high boost to the redline

Something like the HKS or Forge adjustable one will do the trick

jp · 10-12-2006, 18:21

Quote:

Originally Posted by geavesie

what boost controller do you use?

i have had a similar problem to this but i believe it was caused by a badly set up avc-r by myself

AVCR!

Yeah, see the boost is fine at the lower level of 0.6bar but could do with being more stable at 1.2bar. At the moment I've just got the T28R & am looking into the HKS actuator for that - wondering if it'll swop over to the GT28RS if I were to get that one at a later stage?

JP

Rob_B · 10-12-2006, 18:26

damn it...i shud be rebuilding a gt28rs..thats another bill, i'll see how the std one goes with my profec b II

geavesie · 11-12-2006, 07:04

Quote:

Originally Posted by jp

At the moment I've just got the T28R & am looking into the HKS actuator for that - wondering if it'll swop over to the GT28RS if I were to get that one at a later stage?

JP

yeah m8 it should just bolt straight on, they have both got the same compressor housing

it's just the turbine/exhaust housing thats different.

i've got a standard actuator off a standard t28 on my gt28rs because royal mail damaged the original one in the post and they are both identical

bren's supplier tested the damaged actuator and it still held 7psi but it had a nasty great dent in it

anyway how much are uprated actuators?

jp · 11-12-2006, 19:16

Quote:

Originally Posted by geavesie

yeah m8 it should just bolt straight on, they have both got the same compressor housing

it's just the turbine/exhaust housing thats different.

What's the part you need for it to fit back onto the downpipe then?

Quote:

Originally Posted by geavesie

anyway how much are uprated actuators?

Our local trader's latest price!

http://www.sxoc.com/vbb/showpost.php...3&postcount=19

From abroad if you're willing to wait:
http://www.nengun.com/forced-inducti...duty-actuators
http://www.greenline.jp/catalogue/bt...nd%20Actuators

JP

geavesie · 12-12-2006, 07:21

Quote:

Originally Posted by jp

What's the part you need for it to fit back onto the downpipe then?

JP

what do you mean?

you shouldn't need any parts

was it this that you mean?
i said- ""it's just the turbine/exhaust housing thats different""
if so i was just saying that the exhaust housing on the gt28rs is different (bigger) but the actuator clips straight on to the waste gate and bolts onto the compressor housing in exatly the same way as it does to the t28

or

did you mean the turbo elbow?

i'm confussed to what you mean m8

good price for the actuator though

jp · 12-12-2006, 18:47

Quote:

Originally Posted by geavesie

what do you mean?

Sorry man, I'm not the most familiar with all the workings of an engine yet, still learning!

Thought you were telling me there were different parts I needed to fit the RS in-place of the R!

Do I need a different turbo elbow for the GT28RS or will the existing one do? As in are the turbos a straight swop do you know?

Yeah, big enough difference between the prices too!

Wonder how patient I am...

JP

Sideways Danny · 12-12-2006, 18:55

Quote:

Originally Posted by SM

I find this funny, sorry, but a couple of years ago some people were complaining that the 15psi actuator the GT28RS came with was too strong, and they couldnt lower the boost enough, I think mainly due to them trying to use it on stock injectors while they got more funds together for other stuff. So back via suppliers to garret and they supply it with a weaker one, and now we are all turned on its head

the one I fitted for Liquidsmoke about 2 1/2 years ago had to have major bodging done to get it down to 16/17psi. that was the original type housing without the bolt on front flange though (same as I have) with the other housing the standard s14 actuator is a straight fit. mine sits at 10psi lovely with a different bracket fitted

geavesie · 12-12-2006, 19:15

Quote:

Originally Posted by jp

Sorry man, I'm not the most familiar with all the workings of an engine yet, still learning!

Thought you were telling me there were different parts I needed to fit the RS in-place of the R!

Do I need a different turbo elbow for the GT28RS or will the existing one do? As in are the turbos a straight swop do you know?

Yeah, big enough difference between the prices too!

Wonder how patient I am...

JP

the gt28rs is a straight swop if you get the one with the bolt on flange style compressor housing i.e the one with the same housing as the original t28 or gt28r.
and yes the original elbow will fit straight on but might be a good time to put an aftermarket free flowing one on if you have the turbo off the car anyway.
also s14 and s14a elbows are different just make sure you get the right one

i believe some brands might not fit as good as others either.

JulesS14200 · 13-12-2006, 17:52

That actuator in the links does not fit the early version of the GT28rs

jp · 14-12-2006, 00:13

Quote:

Originally Posted by JulesS14200

That actuator in the links does not fit the early version of the GT28rs

How do you know what version of the turbo you have?

JP

10-12-2006, 05:35	#1
jp Holder of the Piston Cup! Join Date: Jul 2006 Location: Dublin, Ireland Posts: 10,555	Does the GT28RS need a stronger... ...actuator? As in if it's fresh out of the box, does it need a strengthened actuator (e.g. HKS) to hold boost steady at 1.2bar? My T28 BB from the S15 is a little jumpy on the way up to when running 1.2bar & I'm wondering would a GT28RS have the same issue at that boost level? I've been told a strengthened actuator solves this issue! JP __________________ BRAND NEW (in the box) Enkei RPF1s For Sale - You need these in your life! GReddy, SARD, HKS, FJO, Z32, Tein, Apexi, Blitz, Cusco parts FOR SALE

10-12-2006, 07:18	#2
geavesie SO YA WANT SOME DO YA Join Date: Nov 2004 Location: scarborough Posts: 907	what boost controller do you use? i have had a similar problem to this but i believe it was caused by a badly set up avc-r by myself have a look at my graph below and see the wavey boost line http://www.sxoc.com/vbb/attachment.p...3&d=1164556720 i have the gt28rs on a standard actuator and it seems fine now the avc-r is set up better __________________ Black 97' S14a - Stage 3 - 320 bhp - 310 lbs/ft - 1.25bar - 13.775 1/4 Mile @ 108.01mph SRB S14A CARBON AND FRP COOLING PANELS FROM AS LOW AS £60 CLICK HERE

10-12-2006, 09:40	#3
archenemy.co.uk formerly Mono Phil Join Date: Dec 2002 Location: Herts Posts: 12,599	I haven't got the turbo but people have posted about this before and the answer is yes, you would benefit greatly from the uprated actuator At the moment your boost controler will have to raise the boost from something like 0.6 of a bar to 1.2. Thats a big jump and it makes the controller work very hard, so hard that it can loose its finer boost control or even just plain can't hold the boost Get the adjustable Actuator and set it to just under a bar then you have a good solid base setting to work from __________________ archenemy.co.uk Arch contact is a thing of the past, no more clenching your butt cheeks over every bump

10-12-2006, 10:42	#5
SteA North West Area Rep Join Date: Aug 2003 Location: Manchester Posts: 7,414	Yes, you do __________________ DCMS - Saving Steves bacon since time began! Specs - http://www.sxoc.com/site/rides/ride.php?Member_ID=1077

10-12-2006, 12:30	#7
Rich_D ex-200SX Owner Join Date: Mar 2006 Location: Lancashire Posts: 4,171	The actuator you get supplied with the GT28RS is actually the same one you get on the standard T28 (I bought one thinking it was better & it's the same one) so it's only rated for 7psi at actuator pressure and it will not hold high boost to the redline Something like the HKS or Forge adjustable one will do the trick __________________ My old S14a >>> CLICK HERE Gone but not forgotten!

10-12-2006, 18:26	#9
Rob_B Guest Join Date: Jun 2006 Location: Norwich Posts: 1,135	damn it...i shud be rebuilding a gt28rs..thats another bill, i'll see how the std one goes with my profec b II __________________ 321BHP ATW ah lovely.........

13-12-2006, 17:52	#16
JulesS14200 RIP Jow :( Join Date: Jun 2004 Location: Algies a c*nt Posts: 13,816	That actuator in the links does not fit the early version of the GT28rs